Why is 'f' appended after time unit instead of frame unit?

[avpromedia]

When I hold down ctrl and click the time display, the timeline ruler units toggles between frame number and time.

For example the tick mark at 1 second would alternate between "00030" and "01:00f"

But why does it append the letter "f" to the time unit? Wouldn't it be more correct to append "f" to the frames display? This is confusing.

[Andrew Yoole]

The f refers to frames.  SMPTE timecode is measured in hours, minutes, seconds and frames. 

HH:MM:SS:ff

It's appended to the timecode reference in AE to differentiate between a decimal time reference versus a frame reference.  For example, at 25 frames per second, each frame lasts for 40 milliseconds.  So in decimal time, 5 seconds and 3 frames reads as 05.12.     But in frames, it's 05.03f.

It's just easier to meaure time in frames in an application that is specifically frame based.

[Warren Heaton]

When viewing Timecode instead of Frame Count, After Effects only shows two of four possible time indicators.  "f", "s" and "m" are used to let the user know which two indicators are being shown.

01:00f is one second and zero frames while 00:01s is zero minutes and one second.  The full Timecode is 00:00:01:00.  The letter shown depends on the duration of your Comp and the Zoom level of your Timeline.

if you edit video, you're likely to use Timecode over Frame Count.  If you do more 3D animation, you're more likely to use Frame Count over Timecode.   Sometimes you use both.

Ultimately, it's up to how you want to measure time.

[jhzxy]

Super confusing. I've spent 2 hours trying to figure out how to read the timeline and change from frames to seconds. Finally got it to change but have no idea what I did.

[Warren Heaton]

Seeing "f" or "s" or "m" or "h" is result of the Composition duration, the horizontal width of the Timeline panel, and the currently zoom level of tbe Time Navigator.

A quick way to see "f" at any time is to use the Zoom In to Frame Intervals keyboard shortcut (;).

Another way is to use Timeline Panel Zoom In (= on the standard keyboard) until h, m, or s switches to f.

[jhzxy]

Thanks Warren. I tried the + and – keys and was finally able to see the seconds with 2 digits and an "S" next to them.